Process for manufacturing rubber shoes



1 641 128 Aug 2 E. w. DUNBAR ET AL PROCESS FOR MANUFACTURING RUBBER SHQES Filed May 5, 1924 2 Sheets-Sheet 1- Aug, 30, 1927. 1 1,641,128

E. W. DUNBAR ET AL PROCESS FOR MANUFACTURING RU BBER' SHOES Filed M21315 2 Sheet5-$h eat 2 Patented Aug. '30, 19 27.

* UNITED f STATES ERNEST W. DUNBAR, OF HUDSON, AND HERMAN 'W'ESTLING, OF BOSTON, MASSACHU I SETTS, ASSIGNORS T CAMBRIDGE RUBBER COMPANY, OF CAIVIBRIDGE, 1VIASS A- ,onusn'rrs, A conronarron or MASSACHUSETTS.

PROCESS FOR MANUFACTURING RUBBER SHOES.

Application filedMay 5, 1924. Serial No. 711,006.

This invention relates to rubber-footwear to improve both the methods ofmakingrub,

her footwear, and also theconstruction of such footwear, with a view to effecting economies in its manufacture. Stated more specifically, the invention aims to reduce the number of parts required in the manufacture 16 of a rubber shoe, to reduce the number of dies required in cutting out such parts as are necessary, to reducethe-waste material, and to simplify the manufacturing operations. 7

no The nature of the invention will be readily understood from the following description when read in connection with the accompanying drawings, andthe novel features will be particularly pointed outin the appended claims. 7 a

Referring now to the drawings,

- Figure 1 is a plan view of the upper of a foot-hold embodying the present invention; i

Fig. 2 is a perspective viewshowing certain of the initial steps in the manufacture of a rubber shoe according to this invention; Fig. 3 is a plan view of the sole blank of a shoe; Q Y

Fig. 4; is a plan view of. a binder strip which may be used in the bottom of a shoe,

if desired;

Fig. 5 is a perspective View of a foot-hold which has just been lasted;

Fig. 6 is a view similar to Fig. 5 showing a lasted shoe after it has been trimmed;

Fig. .7 is a view similar to Fig. 6 showing the shoe after the sole has been ailixed thereto;

45 Fig. 8 is a side elevation of a finished foothold; 7

Fig. 9 is a perspective View showing one step in the manufacture of a bathing shoe according to the present invention; and

Fig. 10 is a view of a tool which may conveniently be used in making the shoe.

In the manufacture of the foot-hold shown, two parts only are essential, namely,

an upper and asole, whereas at least fiveparts have been considered necessary here-j beyond the edge of that part of the blank which will form the vamp of the finished The back strap sections 3'3 project shoe. rearwardly from the vamp.

Preferably the blank 2 is cut out of unlined sheet rubber. If a beading or reinforcement is to be used at-the upper edge of the vamp, or if the toe portion of the shoe upper is to be made heavy or reinforced,

it is preferable to mold or .emboss these reinforcements on the stock by means of a suitabledie or roll, as will readily be under.- stood by those skilled in thisart. Fig. 1 shows such a reinforcement or beading 5 embossed on the upper margin of the vamp. Preferably the edge of each back strap section is first folded over upon itself, as clearly shown in Fig. 2, the turned over portion in creasing in width from the shank toward the rearward extremity, so as to provide ample strength in the strap at the back of the heel.

The edges of the blank are next coated with cement or rendered tacky in any convenient manner, as indicated by the shaded portion at, Fig. 2', and the blank-is then folded longitudinally and the tacky margins pressed together. This folded upper is then drawn over the last and located properly. thereon, substantially as shown in Fig. 5, the joined margins of the upper extending longitudinally of the last in the form of a fin or flange 7. The upper is next pulled snugly over the last by pinching together the surplus portions of the two margins, thus increasing the'height of the fin 7, this operation being continued until the vamp is drawn smoothly over the upper shaping surfaces of the last. The upper is held in this position by the adhesion between the joined margins which constitute the fin 7.

The back strap sections 3-3 are next brought together around the back of the last 6 and joined, as shown in Fig. 5, any surplus stock first being cut off, the surfaces that are to be united being cemented or rendered tacky in order to produce a more perfect union. The surplus portion of the upper forming the pin 7 is next cut off, this operation lacing; conveniently performed with Slitill's. llheu this operation has lieen coinplotted the Wings or extensions of the vamp which now he upon the bottom of the lust are united by ii hutt joint or seem that ex tends longitudinally oi? the laid train the shank to the toe tip. in order to caiuee these two parts to adhere more timely, the po. tionu at each side oi the seam may he wheeled, and for this purpose we prel'er to use a novel tool which W0 have dev ls-ed and whirl isshoivn in Fig. .ltl. llhis tool conip twohvheels 18 adapted to hear siiuiuhirucously on the stock at opposite uidcs of the seem 8, the wheelsv heiug so inclined that they will force the stoelt at opposite t liiQS ol the seam together as the tool rolled over the bottom oi? the shoe. 'lhe indentations or marks leitt by this tool are indicuted in Fig. (3 5 at 9.

It a separate llQlltlilll' strip is used in the place oi. the integral heading indicated at 5, it can he applied at this time. and it a sepu rate tip reinitin'ceniciit, a; ini'licated at ltl is used, this should also he applied at this stage in the proceuu. .hleiiher of these touturcs, however, is essential.

After the trinlujiin jg o ieration has been completed a smooth uni-taro is lel't, tor the reception oi? the role in. This sole simply pressed on to the bottom oi the shoe, as shown in Fig. i. any surplus stock in the shanlcii trimmed oil} and the reuuiining operations nnrv he peril'ornied in any suitable manner. Usually the shoe is next var nished and then vulcanizciuit. The linished shoe in shown in Fig: Fl.

As above tuted. the shoe consists essen tinlly of two pieces, nan'ielv an upper and a sole, and. it; is devoid ot the usual tahrie lin I Oil course, other partu may he added to the upper if desired. hot i'hev are not essential. sometimes preterahle to insure the sole ol' more than one piece. and it is a very eoinn'ion practice to include a hinder strip, such as that indicated at l'lin l, in the hotlom of the uhoe. this hinder consisting o l? ruhheriued .laliri f and heinp; placed innnediately under the sole 1?]. in: indicated at l- L Fig. '7. Various; other nioilitications may he made Without departing; from the spirit or scope oi the invention.

It will he observed that in the shoe i-thoivn the extensions of the vamp Which lie upon the bottom ot the last tor-nu in reality. the insole ot' the shoe. while the part i5 3 consti tutes the outsole. in other words. in this particular shoe the insole and heel; strap are hoth inte rrul with the vamp.

As ahove stated, the invention applicable to other forms o't ruhher foi'itivear. and such footwear niav include a heel portion. For example, Fig. 9 shows: a step in the nninufacture ot a bathing shoe in accordance with this invention. In this case, also, the

upper and insole are integral and the lasting; o niration is: performed suhstantially as ahove ilescrihed, except that the fin 17 extends the entire length oil the lJOtZhOllt and up the hack of the last. After this lusting operation has heen completed the iii]. 7 is trinnneiil oil, a hack stay usually is applied to cover up the sicau'l hetiveen the abutting edges of the upper at the hack ot the last, the outsole is applied, and desired ornanicutol pieces are attached to the upper in. the proper locations, and the shoe then vulcanized.

L lli especially important advantage of this invention is that it eliminates the necessity for dili'ercnt sizes; of upper dies, the same size of upper hlanlc i. n used in making all sizes of shoes. Obviously there is more surplus stoclrto he trimmed oll'in making a email shoe than a large one but this is i111 material since all. this eurplusstock is returi'ieil to the mixing mills ior lie-Working. (the advantage oifthe small number otfiparts required in the inunufacture oit-this shoe will he oln'ious to those sli'illcdin this art. The elimination of the fabric lining" also is eclvonia'greous both because it; avoids the expei'ise of this inati-ariah and also because it saves Waste. That is, it thellanges T and ii, li ies 5 and i) contained .t'u bric, it; would be impossible to rc-worh this stock and use it again in the nninu'lacture of other shoes. The nuinufactoring operutionsarc greatly siinplilioih and consequently the labor eXr peurse involved in the iminuttuctuie oit the shoe is materially reduced.

lihile, as uhove stated. it is preferable to eliminate the fabric lining, it is coute1nplated that such a lining may he desired: under sonic circiunstances, and many ofthei 'tcatur-es ot the present; invention may he used to advantage in a shoe which includes such a lining. For example, a lining may he placed in the inside of the bottom oi the shoe shown in Fin. 8 in order to conceal thescam in the liott 'in'i o't thoslioe, or itorany other llltititlll. Other parts of the shoe also may he lined. ll here the trade denia'zuls such a lining. thereitoro. itnniay he supplied.

l loving: thus deui-rihod miuinvention, whet 11 we desire to claim or; new is: i

l. ll.iat improvement in the processoot.

nnun:l'acturineruhher shoou which consists in providing' an upper oft excessive width, placing: thcuppcr on a last, and adhesivoly securing the marginal ede'eu of said upper to z'ether centrally upon the bottom oli thei 1: i5-:t to hold the up iier in lilo lasted position, with said joined portions forming a fin lcxtending; longitudinally of the last bottom.

.2. that in]provenieni; in the process of inuiuitacturingruhher shoes which consists in cutting: an upper of excessive Width from unlined sheet rnhhcr, placing the upporon a last, odhesively Securing. the nmrginalpom V the bottom of the last to hold the upper inv tions of said upper together centrally upon its lasted position, with the joined margins of the upper forming a fin extending longitudina-lly of the last bottom, trimming off said fin to: provide asubstantially-smooth surface, applying the shoe sole to said surface, and'then completing the manufacture of the shoe in any convenient manner.

3. That improvement in the process of manufacturing heelless rubber shoes which consists in providing an upper of unlined sheet rubber, said upper including a vamp with back strap sections integral with said vamp and with abnormally wide margins at the lower portion of said vamp, folding said vamp longitudinally upon itself, adhesively joining the margins of said vamp together, placing said vamp on a last with saidjoined margins extending longitudinally along the bottom of the last in the form of a fin, drawing said vamp smoothly over the last and holding it in said condition by pinching the surplus stock in said margins together and thereby increasing the height of said fin, re-

moving said fin joining the ends of the back strap sections, and securing a sole to said vamp. V

In testimony whereof we have hereunto signed our names to this specification.

ERNEST W; DUNBAR. HERMAN WESTLING. 

